The invention relates to a dryer with a heat pump, a preferred method for operating the same and a method for air conditioning a room. The method for air conditioning a room especially relates to a method for controlling the temperature and humidity of the air in a room while using this dryer.
In general a tumble dryer is built and operated as a vented-air dryer or condenser dryer. Operation as a vented-air or condensation dryer depends in a number of respects on its installation conditions, especially on the temperature and humidity obtaining in the installation room. Temperature and air humidity in an installation room also influence vented-air and condenser dryers to a different extent.
A condenser dryer, the functioning of which is based on the condensation of the moisture from the laundry evaporated by means of process air in a largely closed circuit, generally does not convey any moisture into an installation room and also makes it possible to recover energy from the heated process air, by using a heat pump for example. The condensate arising in the condenser dryer is collected and either pumped out or disposed of by manually emptying an appropriate collection container.
By contrast, with a vented-air dryer, process air guided in an open circuit and laden with moisture after heating and passage through a laundry drum with the laundry is generally conveyed out of the dryer. There is no heat recovery in this appliance. In addition the air humidity would increase in the installation room; there are therefore numerous regulations stating that the moist process air may not simply be allowed to escape into an installation room, but is removed through a hose or the like from the installation room and the building of which it is part.
DE 30 00 865 A1 discloses a tumble dryer designed as a vented-air dryer with heat recovery. The tumble dryer consists of a container accommodating and agitating the laundry, into which a supply air flow heated by a heating element emerges, while the moist warm air is routed via an outlet as exhaust air. Arranged in the supply air flow in front of the heating element is a heat exchanger through which the moist-warm exhaust air from the container flows.
DE 40 23 000 C2 describes a tumble dryer designed as a condenser dryer with a heat pump in which a supply air opening is arranged in the process air duct between a heat source and a heat sink, represented by condenser and evaporator of the heat pump designed as a compressor heat pump, which is able to be closed off by a controllable closure facility. An exhaust air opening likewise able to be closed off with an assigned closure facility is also present, to enable process air to be removed from the process air duct.
DE 197 37 075 A1 discloses a tumble dryer which is equipped with at least one heat exchanger for heat recovery. Preferably two opposing-flow heat exchangers are used. In a form of embodiment the process air is blown directly into the open air after its passage through the heat exchanger.
DE 197 31 826 A1 describes a tumble dryer with a system for heat return (e.g. a heat pump), in which the largely closed air circuit can exchange the circulating air at two predetermined points through two openings with the air in the room, in order to keep the drying and condensation temperature to the prespecified values.
DE 43 06 217 B4 discloses a programmable tumble dryer with a laundry drum, in which the process air is conveyed through the laundry drum by a fan in a closed process air duct which has closure facilities. The tumble dryer also features a heat pump circuit comprising evaporator, compressor and condenser for removing the moisture in the process air from the laundry drum. The closure facilities are arranged so that the guidance of the process air depends on a process phase.
DE 34 46 468 A1 discloses a method for drying laundry in a tumble dryer with a rotatable laundry drum, a fan, a heater arranged in the flow path of the drying air and also a cooled condenser, via which the drying air is routed after leaving the laundry drum, with the drying air being split up into two part air flows after it leaves the laundry drum. The one part air flow is fed to the condenser and the other bypasses the condenser and is mixed back into the part air flow leaving the condenser.
DE 34 19 743 C2 describes a tumble dryer with a laundry drum, a heater unit provided with a supply air connection and also an exhaust air connection, whereby different supplementary units defining the mode of operation of the tumble dryer are to be arranged for connection between supply air connection of the heater unit and exhaust air connection. In one embodiment of the dryer a recirculation part is connected between the supply air connection flange and the exhaust air flange in which a air control device is located by which the ratio of supply air to exhaust air of the dryer can be varied. This gives the option of a winter-summer switchover. In winter mode cold air is supplied from outside and fed into the dryer. The warm exhaust air of the dryer comes out into the room in which the dryer is sited and contributes to heating up the air in the room.
EP 1 559 829 A describes a laundry drying machine which has devices for directing a partly dehumidified air flow back into the drying air flow. Switchover devices are present which can be set so that the laundry drying machine can be operated simultaneously by means of an open circuit and a closed-circuit, with the relationship between the flow rates in the open circuit and in the closed circuit able to be set and defined.
DE 197 25 536 C2 describes a method for controlling the heating power of a tumble dryer, especially a vented-air tumble dryer, with a drying chamber with an air inlet and an air outlet, with a heating facility arranged before the air inlet and with a program control for controlling the heating facility, with a room air temperature TR, being measured via at least one temperature sensor before the heating facility is put into operation with the process air fan switched on and also at least one further temperature value T2 occurring after a defined period of time before the heating is put into operation. The heating is then activated by a microcomputer as a function of room air temperature value TR and a relative air humidity YR of the room air determined on the basis of this data.